First of all, thanks to @ilovemeow and @tomparr !
We all know, it was on the Moto X Play easy to "unlock" the DualSim ability by flash a firmware with including a DSDS Baseband. But Moto changed the Firmware layout. On the Moto Z Play are all basebands in the /fsg folder and after a modem wipe (dualsim=true or false) loads the matching baseband to modemst1 and modemst2. The settings for dualsim=true and the software channel are not editable right now.
So the trick is to get the baseband for dualsim in to the modem. I found a easy but dirty way to get the DSDS baseband loaded.
You need a Moto Z Play SingleSim Device (Mine is from Germany with RETEU)
Now the step by step guide:
1. boot in to twrp open the terminal and type
setprop persist.radio.multisim.config dsds
2. boot and make sure you got the Dualsim options in the Settings. If yes goto 3. If not load a Terminal Emulator from playstore and type there the command from 1.
3. Got to the settings and look which baseband you use now! Its important to note that!!
3. Open the RootExplorer and navigate tot he fsg Folder. You will find there a bunch of im.gz files (like addison_2.img.gz and addison_dsds_2.img.gz and so on…)
4. You must make sure which file for your phone is the right one (For the EU Phones its Addison_ROW and addisson_2.img.gz) You will see that the numbered files are linked to the other file in the folder. See the Picture.
5. Now you have to delete the baseband your phone use normally. At the EU Devices addisson_2.img.gz and addisson_row.img.gz
6. Now comes the magic! xD Just rename the dsds files from addisson_dsds_2.img.gz to adisson_2.img.gz and addison_dsds_row.img to addison_row.img.gz.
7. Reboot to bootloader and enter
fastboot erase modemst1 fastboot erase modemst2 fastboot erase cache fastboot reboot
now you can use both cards!
1. there some bugs in the dialer! You cant save the settings that a specific number automatic called by sim1 or sim2
2. Second SIM Card/Modem only got IMEI 0! But works in German Networks without a problem.
3. You can loose your of sim1/modem IMEI if you do something wrong!
4. You got a bit more battary drain.
5. You can restore the default settings with just flashing the fsg.mbn file!
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